Underreamer.



J.. M. JDIELMQRB.

MNDBRRB'MER.

,wrvmwaxmloumnnn 821,128. 1910.

'.1;@06,446. 'Patented 0cm?,

27 I 75 QQ Y, s :vs

1" *282g l I' JOSEPH M. DELMORE, OF PIRU, CALIFORNIA.

U'Nnrznmsamnn.

Specification of Letters Patent.

Patented Oct.' 17, 1911.

Application led September 28, 1910. Serial No. 584,371.

To all whom 'it 'may concern:

Be it known that I, JOSEPH M. DnLMoRE, a citizen of the United States, residing at Iiru, in the county of Ventura and State of California, have invented a new and useful Underreamer, of which the following is a specification.

The main object ofthe present invention is to provide an underreamer which will n present cutting surfaces covering substantially a 'complete circle, thereby obviating the liability of the underreamersto cut a flat or non-circular hole and insuring the formation of a hole which will allow free 5 descent of the casing. y f

A further object of the invention is to provide an underreamer in which the several parts are' located in operative position in such manner as to form a substantially rigid structure.

' Another object of the invention is to provide means for retaining the cutters and their supporting members in place during the operation, the retaining means being releasable when required to remove the cutters.

Other objects of the invention will appear hereinafter.

The accompanying drawings illustrate the invention, and referring thereto: Figure l :ois a vertical section of the underreamer in operative position. Fig. 2 is a similar view showing the underreamer in collapsed position and entered within the casing. Fig. 2 is a vertical section of the underreamer with l5 the parts in position for withdrawal of the cutters from the body of the tool. Fig. 3 is a horizontal section on line :vs in Fig. l. Fig. 4 is a horizontal section on line :vh-w* in Fig. 1. Fi 5 is a vertical section of the l0 upper part o the device at right `angles to Fig. 1, showing the parts in position for releasing the cutters. Fig. 6 is a vertical section of a retaining plate for the underreamer cutters. Fig. 7 is an invertedl lan 6 thereof. Fig.'8 is a vertical section o the means for supporting said plate.

1 designates the body of the underreamer which is tubular and is adapted to enter freely within the casing 2, said tubular body 1 being adapted to .be secured by screw socket 1', in the usual manner, to the lower end of the usual operating means 2 therefor. The lower end of thetubular member 1 is formed with a frusto-conical recess 3 adapted to receive and t the upper'ends of the cutters 4 when said cutters are in operative position. Said cutters are held in such position by locking means consisting of a ,bar 5 slidable in a partition or flange 6 extending at the lower end of the axial recess 7 in the tubular member 1, said bar.5 carrying at its upper end a head 8 engaged by a spring 9 whose lower end engages with the flange 6 aforesaid, so as to tend to raise said bar, and said bar being provided at its lower end with means for engaging the several cutters 4. Bar 5 is square or` non-circular and the hole in flange 6 is correspondingly formed `to prevent rotation of 4said bar. Head 8 is fast on bar 5, being, for example, screwed on said bar 5, and held by jam nut or screw collar 8.

The cutters 4 are segmental in cross section and are of such circumferential length as to extend substantially around a complete circle. Any desired number of cutters may be used, three being the preferred number, each cutter being then approximately 120 in segmental length. I prefer to use three or more cutters for the reason that the cutters will then move in different radial directions, the angles between said directions being less than 180, so that as the cutters move inwardly and outwardly, they Vdo not move directly but obliquely to and from one another, and the circumferential separation of their outward movement is therefore less than 4when they move directly to and from one another. Consequently with three or more cutters, the cutters when in operative expanded position present less space between them than is the case with only two cutters and extend substantially around the complete circle so that the possibility of cutting a flat hole is avoided. The cutters 4:. are provided with cutting edges ,4' at their lower ends and with faces 10 at their upper portions formed as conoidal segmental surfaces adapted to fit within the frusto-conical recess 3 aforesaid, and the upper ends of the cutters '4 are adapted to fit against the upper end of said recess, the top of said `recess being preferably dished slightly upward andl the cutters being inclined upwardly and inwardl at their upper ends m correspondence t erewith. At the lower ends of the bearing surfaces 10 the cuttes are formed with shoulders 11 `adapted to engage under the lower end ot' the tubular body 1 and at a lower point on the cutters there is provided on the outside of the cutters an enlargement or shoulder 12 adapted to engage with the lower end said plate withthe of the casing as the' cutter is being drawn thereinto. The inner faces of the cutters converge or taper inwardly and upwardly, as-shown at 13, such converging portions terminating in vertical faces 14 adapted to lit the respective sides of a polygonal block 15 on the lower end of the bar 5. With the stated constructionl in which three cutters are provided, this block is preferably of triangular cross section having three flat faces 15 engaging with the respective faces 14 of' the cutters. A spring 16 bears against this block and against a ring 17 slidably mounted on the bar 5,'said ring 17 engaging with, grooves 18 inthe cutters to hold the cutters in place, as hereinafter set forth.

I prefer to provide meansv whereby the locking vbar is retained or prevented from' moving downwardly to more than a limited extent in the ordinary operation of the device, so thatthereis no possibility of the A .cutters 4 becoming loose or detached in such operation. Such retalning means comprises a plate 20 slidably and non-rotatably mountyed on a squared stud portion 21 `at the upper end of the locking bar 5 above the head 8 thereon, said vplate 20 having projections or lugs 23 adapted to extend over a shoulder 24 on the tubular body 1 and the stud 21 havinga Anut 25 screwing on the upper end thereof and engaging over the plate 20, so that the downward movement of the locking bar 5 is limited# by the engagement of said nut with the plate 20 and of the lugs 23 on shoulder 24. Vertical slots 33.l are provided in the tubular body -l extending downwardly from the shoulder `24 a suflicient distance to allow the lugs 23 to 'pass downwardly when in register therewith, so as to allow the locking bar to drop far enough for release of the cut-ters 4 from the recess 3.A In order to release this retain- `from said lngmeans when it. is desired to detach the cutters, the :plate 20 is provided with a cap 26 secured there-.to as by rivets 26 and extending over. the nut 25 and stud 21, said cap adapted to receive a bar 28 (see Fig. 5) which is inserted through va longitudinal bore 28 in .thelocking bar 5 said bore extending through block 15 and beingscrew.

threaded to receive an eyebolt 32 (Fig. 23). The stud121 is provided below the squared portionl thereof with a rounded portion 30 to enable the plate 20 to be drawn down oi' of said squared portion, and a spring 31 is provided seated against the head 8 and engaging said plate 20 to normally raise said plate into position surrounding thev squared.

portion 21. Inthe normal position of the parts shown in Fig. 1, the plate 21 will be held somewhat abovethe shoulders 24, so

that the lugs 23 on said plate are separatedshoulder. By insertingthe bar erator.

26- having'fa central tapped hole `27 28 aforesaid through the bore 28 and screwing it into the hole,.27 and then drawing down on said bar, the plate 20 may be pulled off of the squared portion of the stud 21 and may then be turned a quarter turn bringing its lugs 23 in line with the slots 33 in the tubular body l1. The locking bar 5 with the parts carried thereby, including the cutters, and the locking block 15 are then drawn down sufliciently (as shown in Fig. 2a) to allow the cutters to be slipped out from within the recess 3, the bar 28 being first withdrawn and an eye-bolt, indi-- said bar 28 is of suliicient length to enable it to extend up in the bore 28 into engagew ment with the tap hole 27, while its lower end projects below the bottom of the underreamer into position to be grasped by the handsof the operator and the eye-bolt 32 is alsoof sufficient length to enable it to extend into position to be grasped by the opvertical walls 14, as shown at 29, to provide The cutters are -recessed above thel a space for receiving the `parts above `desame is elevated, as hereinafter set forth. The shouldert29 at the vbottom of recess 29 and the lower face 14 of block 15are pref.-

erably'inclined to enable the said block t be pushed into position between the flat faces 14 of thecuttersby the action of the spring 16.

scribed and to receive theblock 15 when the In entering the underreamer into-the .case

ing, the cutters are gripped by suitablemeans and drawn .outwardly so as, to enable V the shoulder 29 .to slip over the outer endA ofthe bloclr l15 and to Ienable said block to enter recess 29 .and the cutters to bev col-l lapsed into position, (shown in Fig. 2), in

which they mayk be entered within the .cas"

ing.` In this operation the spring 16 is compressed and the spring 9 is also compressed, the' bar 5 being drawn downwardlywithin the body entered within the casing, andv While it is 1. The underreamer is then4V passing through the casing, the cutters are held in collapsed position byvengagement of the shoulders 12 with the wall of the casing. When the underreamer reaches the bottom of 4the casing, the cuttersare forced outwardly by the action of the inclined faces of the block 15 and shoulders 29 this action being producedy -by the pressure of spring v 16 which moves the block 15. into position between the vertical faces 14 of the cutters, as shown in Fig. 1. At the same time the spring 9 moves the cutters and bar 5 bodily upward, causing the upper portions orl Shanks-of the cutter to be seated in the conical-recess 3 of the body 1. When the blocks are movedI outwardly, as stated, to

operative position shown in Fig, 1, the

shoulders 11 are under the tubular body 1,

their bearing faces fit within the frustolf conical seat 3 in the tubular member 1 and their upperends 24 it against the dished upper end of the said recess. As the triangular block 15 fits tightly against the several cutters, it, is apparent that the cutters are located in tight contact with the tubular body 1 forming a substantially rigid structure.4 Tight contact at the uppeil ends of the cutters is insured by the ring 17, the spring 16 operating through said ring 17 to press the cutters upward and/cause their upper ends to bear upwardly and outwardly on the walls of the recess 7. In withdrawing the underreamer tension is exerted on the tubular body 1, in the usual manner, to

draw the cutters upwardly within the cas-- ing, and on account of the outward flare of the cutters, the ascent of the cutters is resisted by reason of,y the engagement of the cutters with the casing and as the upward movement of the tubular body 1 is continued, said body moves away from the cut. ters, the springs 9 and 16 being compressed and the bar 5 being drawn upwardly until the locking block 15 at the lower end thereof'snaps into the interior recess 29 within the cutters. This removes the obstruction to the inward movements of the cutters and in the farther upward movement of the tubular member 1 they cutters are collapsed by the engagement of their outwardly flaring outer faces with the casing 2, 'so that the `underreamer as a whole may be withdrawn through the casing 2.

What I claim is:

1. Ap underi'eamer comprising a tubular body having a recess in its lower end, three or more cutters, seated in said recess, said cutters extending in conjunction throughout a complete circle, and mounted to move in diHerent directions, the angles between said directions bein less than 180, and said cutters being` ormed interiorly with vertical faces and with recesses above said vertical faces,-in combination with a locking member slidable vertically within said body, and provided at its lower` end with a block adapted to tit between the vertical faces of the cutters to hold the cutters out-4 wardly to operative position, and to move upwardly into said recesses to allow the cutters to move inwardly, and means interposed between said cutters and said locking ar to raise and lower the cutters by operation of the locking bar, and to allow limited relative movement of the cutters and locking bar.

2. An underreamer comprising a tubular` body having a recess in its lower end, a p1u l rality of cutters seated in said recess, said cutters extending in conjunction substantially throughout a complete circle, and being formed interiorly with vertical faces, and with recesses above said vertical faces, in combination with a locking bar slidable vertically within said body, and formed at itslower end with a block adapted to fit between the vertical faces of the cutters to hold the cutters outwardly to operative position, and to move upwardly into said recesses to allow the cutters to move inwardly, a member slidable on the locking bar, and engaging the upper portions of the cutters to raise and lower the cutters by operation of the locking bar, and a spring interposed between said member and said locking bar to force the cutters upward.

3. In an underreamer, the combination with a tubular body having a recess at its lower end and a plurality of cutters having their upper portions seated in said recess, of a locking bar slidably mounted in said tubular body and provided with means for engaging said cutters to hold the same within said recess, a spring tending to hold s aid locking bar in elevated position, retaining means mounted at the upper end of said locking bar and ,provided with projecting means, said tubular body havin a shoulder adapted to be engaged by said projecting means to limit downward movement of said locking bar and having slots to receive said projections in a certain position thereof to permit farther downward movement for release of the cutters, said retaining member being movable to bring the said projecting means thereon into and out of cooperative relation with said slots in the tubular body. v

In. testimony whereof I have hereunto set my hand at Los Angeles, California, this th day of September, 1910.

` JOSEPH M. DELMORE." In presence off ARTHUR P. KNIGHT,

FRANK L. GRAHAM. 

